I remember seeing a film when I was a kid (early 80's), and from what I remember, at the end, a cleaning woman walks into a dark damp cell of a room and turns on the light by pulling a string, and as soon as she does this a severed head falls from the ceiling into her mop bucket; would anyone happen to know what this film would be called, it would be highly appreciated and my dad would love to know the movie's title also.